Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 9 of 9

Full-Text Articles in Life Sciences

The Genetic Architecture And Evolution Of Brain Cortical Folding In A Pedigreed Primate Population, Elizabeth Grace Atkinson Dec 2013

The Genetic Architecture And Evolution Of Brain Cortical Folding In A Pedigreed Primate Population, Elizabeth Grace Atkinson

Arts & Sciences Electronic Theses and Dissertations

Elevated neurological faculty, related to the dramatic increase in brain volume, is a hallmark of the primates. Cognitive capacity, the processing power and speed of the brain, is directly related to the number of neurons in the cerebral cortex and the connectivity network underlying information processing in the brain. Increased cortical folding (gyrification) allows for more neurons to be contained within the volume of the braincase and the arrangement of folds and ridges across the cerebral cortex is an indication of the underlying neural network connecting regions. The goal of this dissertation is to develop a better understanding of the ...


The Natural Variants Of The Streptococcus Nad+-Glycohydrolase Spn Modulate Divergent Host Cell Signaling Pathways And Death, Sukantha Chandrasekaran Aug 2013

The Natural Variants Of The Streptococcus Nad+-Glycohydrolase Spn Modulate Divergent Host Cell Signaling Pathways And Death, Sukantha Chandrasekaran

Arts & Sciences Electronic Theses and Dissertations

Streptococcus pyogenes has an arsenal of virulence factors that promote its ability to cause a broad range of diseases and fight host defenses. One of these factors is the S. pyogenes NAD+-glycohydrolase (SPN), which is secreted from the bacterial cell and translocated into the host cell cytosol where it contributes to cell death. Every strain examined to date has SPN and recent studies suggest that SPN is continuing to evolve diverging into two variants that correlate with tissue tropism, one of which lacks the signature NADase activity. SPN's roles in both cytotoxicity and niche selection are unknown. To ...


Development Of Polarizable Force Field Models For Transition Metal Ions, Jin Yu Xiang Aug 2013

Development Of Polarizable Force Field Models For Transition Metal Ions, Jin Yu Xiang

Arts & Sciences Electronic Theses and Dissertations

This dissertation focuses on the development of polarizable molecular mechanics (MM) force field models for the third-row transition metal (TM) ions. These TM ions perform important structural and chemical functions in a wide range of organic and biological environments because of the unique properties of the 3d orbitals. Being able study these systems in silico can provide a tremendous amount of information that is difficult to obtain through experiments. However, the standard treatment of ions in traditional MM models has shown to be insufficient for describing the d-shell electronic effects. In this work, empirical models for TM electronic effects are ...


Post-Translational Regulation Of Fas-Mediated Pparα Activation, Anne Patricia Louise Jensen-Urstad Aug 2013

Post-Translational Regulation Of Fas-Mediated Pparα Activation, Anne Patricia Louise Jensen-Urstad

Arts & Sciences Electronic Theses and Dissertations

The liver is a central organ to whole-body metabolism and mediates many of the adaptive responses to changes in nutrient availability, such that the appropriate energy sources are used and blood glucose levels maintained, whether directly after a meal or after a twelve-hour fast. The adaptive responses to fasting in liver are largely mediated by the nuclear receptor peroxisome proliferator-activated receptor α, or PPARα.

PPARα can be activated by a de novo synthesized lipid ligand—16:0/18:1- glycerophosphocholine (16:0/18:1-GPC)—the synthesis of which is dependent on fatty acid synthase (FAS), but little is known about ...


Quantification Of Conformational Heterogeneity And Its Role In Protein Aggregation And Unfolding, Nicholas J. Lyle Aug 2013

Quantification Of Conformational Heterogeneity And Its Role In Protein Aggregation And Unfolding, Nicholas J. Lyle

Arts & Sciences Electronic Theses and Dissertations

Proteins can exhibit significant conformational heterogeneity either under denaturing conditions or in aqueous solutions. The latter is true for a class of proteins whose sequences predispose them to form heterogeneous ensembles of conformations. Characterization of conformational heterogeneity in a protein ensemble requires the quantification of the amplitudes of spontaneous fluctuations in conjunction with information regarding coarse grain measures that report on the average sizes, shapes, and densities. This often demands multiplexed experimental approaches whose readouts are interpreted or annotated using ensembles drawn from atomistic or coarse grain computational simulations. Efforts to characterize conformational heterogeneity contribute directly to our understanding of ...


Type 1 Diabetes And The Male Reproductive Axis, Erica Schoeller Aug 2013

Type 1 Diabetes And The Male Reproductive Axis, Erica Schoeller

Arts & Sciences Electronic Theses and Dissertations

Glucose regulation is important in both spermatogenesis as well as mature sperm function. The impact of diabetes on sperm function is becoming increasingly clear, though much work is still needed to elucidate the mechanism by which diabetes impairs spermatogenesis. Diabetes causes disruptions in the hypothalamic pituitary gonadal (HPG) axis, the regulatory system that controls reproduction. The HPG axis functions by secreting GnRH pulses from the hypothalamus, which bind to receptors on the pituitary and cause secretion of follicle stimulating hormone and luteinizing hormone, which then bind to receptors in the testes and facilitate spermatogenesis. Type 1 diabetes can severely impact ...


Dysfunctional Gene Regulation Of The Meiotic Program In An Interspecific Yeast Hybrid, Devjanee Swain Lenz Aug 2013

Dysfunctional Gene Regulation Of The Meiotic Program In An Interspecific Yeast Hybrid, Devjanee Swain Lenz

Arts & Sciences Electronic Theses and Dissertations

Speciation, the evolutionary process by which species arise, is a fundamental biological concept. One of the major goals of evolutionary genetics is to understand the genetic basis of reproductive isolation (RI), a collection of barriers that prevents two species from forming viable or fertile hybrids. Given the lack of viable or fertile hybrid progeny, identifying genes that impact RI as well as their functions has been difficult. Thus we lack a view of the total genetic contribution to RI. Recently the budding yeast Saccharomyces has served as an evolutionary model, as abundant sequence, expression, and phenotypic data exist for the ...


The Uropathogenic Escherichia Coli Effector Ybcl Modulates The Innate Immune Response In The Urinary Tract, Megan Elizabeth Lau Aug 2013

The Uropathogenic Escherichia Coli Effector Ybcl Modulates The Innate Immune Response In The Urinary Tract, Megan Elizabeth Lau

Arts & Sciences Electronic Theses and Dissertations

Uropathogenic Escherichia coli (UPEC) are the primary etiology of urinary tract infections (UTIs), one of the most common bacterial infections afflicting the human population. While UPEC cause disease throughout the urinary tract, bladder infection, or cystitis, is most prevalent. A key aspect of UPEC pathogenesis in the bladder is the modulation of the host inflammatory response. At acute time points, UPEC delay the arrival of immune cells, such as neutrophils, to the bladder. The lack of neutrophils in the bladder lumen enables UPEC to replicate freely in the urine and invade the bladder epithelium, a requirement for bacterial persistence, in ...


Urine Trouble: A Molecular And Anatomical Examination Of Bladder Pain, Lara Wiley Crock May 2013

Urine Trouble: A Molecular And Anatomical Examination Of Bladder Pain, Lara Wiley Crock

Arts & Sciences Electronic Theses and Dissertations

Interstitial cystitis or painful bladder syndrome (IC/PBS) is a chronic pain syndrome affecting 3-6% of women in the US. Some evidence suggests urothelial injury may cause some cases of IC/PBS. To examine how urothelial injury modulates bladder pain, three injury models were used: Infection with uropathogenic Escherichia coli (UPEC, inflammatory), Protamine sulfate (PS, non-inflammatory chemical), and lipopolysaccharide (LPS, non-infectious and inflammatory) treatment. Surprisingly, injury with PS decreased, while UPEC alone increased the pain response to bladder distention. These data suggest that changes in the urothelium may modulate some forms of IC/PBS. However, in most cases, patients with ...